Absorbent bodies for absorbent articles, such as disposable diapers, panty diapers, sanitary napkins, incontinence guards and the like, are commonly manufactured by delivering fibrous bodies on a moving web and thereafter compressing the bodies by passing the bodies through the nip between a pair of rollers. By adjusting the nip between the rollers, a desired density of the fibrous bodies can be obtained in order to give the bodies sufficient mechanical strength and appropriate capillary action. If the fibrous bodies have portions with different basis weight, such as a thicker portion in the central crotch part of an absorbent article, the compressing of the thin portion can be made by a pair of rollers having a cut-out to accommodate the thick portion of the body, the compressing of the thick portion being made by a separate pair of rollers or by the inner wall of an appropriate dimensioned cut-out. If the thick portion is not wholly accommodated in the cut-out, the parts thereof lying outside the cut-out have to pass a portion of the nip between the rollers, which is dimensioned for compressing the thin portion of the fibrous body. If this occur, there is a great risk that the desired density in the thin portion of the body will not be obtained. Furthermore, the parts of the thick portion lying outside the cut-out will be compressed to an unduly high density, the fibers in the body might break and capillary action might be lost in these parts. The thick portion can also be so thick that it can not be compressed to such an extent that it can pass the nip between the rollers, leading to a stand still in the manufacturing process. For these reasons the area of the cut-out is made somewhat larger than the area of the thick portion of the fibrous body. The difference between the areas of the cut-out and thick portion of the fibrous body is of course dependent on the accuracy of registration of the thick portion of the bodies laid on the moving web and the cut-out or cut-outs on the rotating rollers. However, even if the accuracy is high, such a difference in areas must be present in order to ensure that the thick portion of each fibrous body will be accommodated within the cut-out or a cut-out in the pair of compressing rollers.
As a consequence of the difference in areas of the thick portion of the fibrous body and the cut-out in the roller there is, in the thin portion, a boundary region around the edge of the thick portion that remains uncompressed after passage of the nip between the rollers. This boundary region has very little mechanical strength and will easily break.